ASTM D3606 Capillary Options: Products and Tips for Getting Started

ASTM method D3606 is used to separate benzene and toluene in spark ignition fuels. Analysts may use capillary (option A) or packed (option B ) columns for this method. The capillary option uses two columns connected in a series, where the first column is nonpolar dimethylpolysiloxane phase (Rxi-1ms, cat# 13338) and the second is a polar “wax” phase (Stabilwax, cat.# 10657 ) column. After toluene is eluted from the first column, the first column is backflushed while an auxiliary EPC maintains flow through the second column. The complicated setup associated with the ASTM D3606 capillary option may make the method unappealing, but the results show excellent separation of target analytes. We used Restek’s Rxi-1ms and Stabilwax to separate target analytes in D3606 standard 8.5.2 and a sample of gasoline and generated helpful tips for getting started and troubleshooting this method. Future work may consider performance of this column set for a full method validation and potential limitations.